Fix crash on Wii VC caused by Fado spawn hack for adult trade shuffle

[mracsys]

The previous hack in EnKo_CanSpawn saved register $ra to temp register t3 before jumping to a custom function controlling Fado's spawn behavior. While the N64 and emulators handled this without problems, Wii VC and Dolphin frequently but inconsistently crash with this code. The spawn hacks are revised to move the custom function call to the end of EnKo_Init after EnKo_CanSpawn is called, eliminating the need for caching any registers.

The crash is difficult to reproduce consistently, but with these changes it hasn't happened through >100 actor spawns using the attached plando. Odd Potion is in the top left chest of Mido's House for easy tests for all of Fado's spawn conditions.

trade-quest-rework-adult-fado.txt

Thanks to RealRob, flagrama, and Retropolis for identifying the possible cause.

[rrealmuto]

Assuming the original theory on why this crashes in the first place was correct, this new hack looks like it should fix the problem. However I'm concerned that without some additional checks it may inadvertently prevent spawning other kokiri actors.

[rrealmuto]

Only request would be, in the spirit of improving how we organize the hacks, to move the new fado hacks out into their own file. Otherwise these hacks look good.

[mracsys]

Is there a preferred filename to move it to? Or put it with the rest of the trade quest hacks in trade_quests.asm?

[rrealmuto]

so my preferred way of organizing hacks is placing them in ASM/hacks/ovl_nameofoverlay.asm and then including that at the bottom of hacks.asm

so for this, a new file ASM/hacks/ovl_en_ko.asm

[rrealmuto]

Looking at reorganizing things a bit with #2354 but that name should be good to go along with that

[rrealmuto]

🥰

[rrealmuto]

This looks good to me. Also Rebbacus offered a pretty good explanation of the original crash over in the discord.